Mustard algae questions

[AimeeH]

I'm not a newbie at TFP (supporter, TF100, etc). I slammed properly at opening in March. Took out lights and all. I never went to mustard algae shock level but I think that is my problem now. Pool had been crystal clear until last Friday.

Does mustard algae consume your chlorine at a higher rate than others?

Saw algae last Friday evening. Because I have SWG I hadn't been testing water daily, but weekly. After initial slam, SWG was keeping FC at around 7 when I tested on weekends. It is set to run 11am-6pm at 40%. Weather finally got (really) warm and last Friday I saw algae. Tested chlorine within an hour of pump going off and FC was 3.5. Cya had been 45 and I added enough to bring it to 65 after initial spring slam.....that worked. Tested CYA two weeks after addition and got 65 two days in a row.

So my best guess is that I was still within min CL.

So now....been slamming since Sunday (after seeing the algae) Keeping CL in the 30 range. OCLT showed 0 change overnight (SWG off, only used bleach for that) last night.......so here is my question/conundrum. I knew I wouldn't be home today (gone from 7am-9:30pm....kids ) so I told hubby to turn on SWG. I told him to set it at 60%. We were still above shock level this morning so I added no bleach this morning. Upon testing at about 10pm we were down to 22ppm FC after SWG running ALL day at 60%. The morning started at 30+ .

There is potential that it was testing error (on OCLT )...but I don't think so. Hubby is now assigned to be my back up counter of drops.

We passed slam in March. I didn't "think" my CL had ever dropped below min. I'm going to proceed with slam and then elevate to mustard this time but was wondering:

If mustard might be responsible for the unexpected loss during the day?
Should I really take lights out again? (The cavities were all clean last time in April/march)?
And I might be looking at a cell failure?.....although it was maintaining prior to last weekend.

 

[frustratedpoolmom]

Even with CYA you lose a lot of FC, especially when your FC level is higher. The higher it is, the higher % of the loss. Even with the SWG on. Since this isn't probably something you've tested to check before, it seems alarming. With CYA you lose like 50% of your FC to sunlight. Without, it would be 100%. So in theory it could have been like 15 without the SWG running... does this make sense?

Did you take a pic of the algae? I'm guessing it's not mustard algae tho. That's actually quite rare.

 

[AimeeH]

Thanks for the reply. I have a pick from last year. Same stuff, same shaded area.

I had not added to the post that I started shock with just enough dichlor to go ahead and raise my CYA a bit. As an SWG owner, I'm lazy about bleach bottles. I added enough dichlor to raise cya by about 12 and then moved to bleach. So really I was even using slam numbers for higher than 65 and was looking at the 70 range......which I would have thought would slow down that CL daytime loss.

It is baffling me. I'll do OCLT again tonight. FC tested at 33.5 with SWG off and one hour after adding bleach.

The daytime loss has me baffled. And I do think it is mustard. It comes back at the same spot with seemingly "normal" CL levels.....it brushes into a cloud....etc.

I was just wondering if FC demand is significantly higher with this strain of algae.

 

[AimeeH]

SWG running at 60% all day.....from 7am-10pm shoul have kept me in range ...I would have thought. Running at 40% it was keeping me at the 7 range for weeks.......or so I thought.

Getting better at isolating problems......still asking questions to those who have more experience than me.

 

[chem geek]

If you have a lot of algae then you could notice an increase in chlorine demand, but this algae doesn't increase it any more than green algae -- it's pretty much a per volume thing. You may be correct that your cell isn't outputting as much or you could have stronger sunlight this time of year. You could do an overnight chlorine loss test (OCLT) to distinguish between sunlight losses and other losses. A SLAM to yellow/mustard algae levels is a bit of a pain but could kill off this algae if you expose it to such levels wherever it is currently hiding. As for the niches, it would be safer to pull out the lights during the SLAM to expose them to high chlorine levels.

If you are unable to get rid of this algae or it's just too much work for you to do so then the other alternatives are to maintain a higher FC/CYA ratio that is roughly double the normal minimum or you can use supplemental algaecide products but Polyquat doesn't do so well with this algae so it's pretty much using a phosphate remover since I don't think you want to use sodium bromide and turn your pool into a bromine pool.

 

[AimeeH]

Thanks for the info chem geek. Because I think I've been pretty diligent with my SLAM's and this returns (in the same shaded areas) at seemingly normal CL levels, I'm thinking mustard algae. I'm planning on elevating to mustard level this week and maintaining for 24 hours then crossing my fingers.

The large FC loss between 7am and about 10pm with SWG at 60% is what had me puzzled.

I need to perfect my timing too. The last two OCLT's actually showed an INCREASE of FC by 1 and 1.5 respectively. I was only waiting an hour after bleach addition to get base test for OCLT. SWG is off at these times so clearly I need to circulate more before testing. Because of that.....I'm not yet convinced of truly passing OCLT.

SWg is off all day today. CL was at 35 this morning (yep 70 drops). I'm looking forward to seeing what daytime loss is today. Still getting to know this baby.

 

[ping]

I would not be too concerned about the daytime loss and just concentrate on the overnight loss. With a high FC amount the losses are more dramatic during the day than when the FC is at normal levels.

 

[AimeeH]

I was not so much concerned with quantity of FC lost during daylight but really had expected my SWG to maintain it better running at 60% all day. I was a bit surprised.

 

[duraleigh]

It comes back at the same spot with seemingly "normal" CL levels.....it brushes into a cloud....etc.
I was just wondering if FC demand is significantly higher with this strain of algae.

This response is anecdotal so I don't have anything to back it up.

I have had a nice dose of Mustard Algae that appears usually in late Summer. If anything, it SEEMS like my FC loss is perhaps less than if it was green algae. I can't verify that with numbers but I am embarrassed to say I have had it several times in the past nine years and I cannot detect any additional FC loss.

 

[AimeeH]

I appreciate your post even if anecdotal. Because of the way this appeared I'm feeling like it is mustard algae.

On a different note.....my SLAM has been hijacked by a rain storm. Not just any rain storm but a rainstorm that practically caused the pool to overflow. My 2acre pond was up well over a foot (maybe 2) and was not far from going over the dam. All efforts upon getting home from work at 5:30 were to increase water flow at the dam overflow.....it was kind of panic time. Physical labor spent trying to clean out the overflow with hoes (this overflow comes into play maybe once every two years). Never seen the water that high in 10 years here.

When all that could be done was done I just sat here and looked at the pool thinking......I know I need to go check that chlorine and brush. But I'm pooped.

I'll try tonight. Might be interesting to see what THAT much rain dilution did. Still haven't been able to backwash it below the top of skimmer boxes.......after at least 10-15 minutes of pumping...had to tend to the dam.

 

[Casey]

Dang Aimee! That's a lot of work for you!

 

[AimeeH]

I've never seen that much rain in such a short period of time. It was on the news that evening that an isolated area (where we live) actually received 6 inches of rain that afternoon. I tested my CYA this afternoon and it was down to 50 from 65. I didn't think that was possible but I just estimated pool volume with an additional 6 inches of water and it doesn't seem too far off .......the pool vas very near overflowing onto concrete deck. I didn't see it as hubby was already draining when I came home but he said he was pretty sure it was at the top of the liner track.

Returning to slam and am gonna fix this ! Also found algae growing in the holes of the skimmer lids......hadn't noticed that before.

Different subject but would damage from water going above liner track and getting behind liner track show up quickly ? I haven't yet noticed any new wrinkles or any of liner looking "floated"

 

[chem geek]

I forgot to mention that poor circulation in an area can also lead to algae growth especially with yellow/mustard algae since it really takes advantage of any low chlorine situations. So pointing returns in a different way to change circulation patterns may sometimes help.

 

[AimeeH]

Thanks chem geek. I do know that and the area it always returns is just such an area. I will certainly be more diligent about brushing that area and I've already tried turning the eyes.

Since I'm a relatively new pool owner, I have no familiarity with equipment beyond what I have. Would there be better quality "eyes" (?) than what my builder would have installed that would have better directionality?

I have a total of 7 returns (I think...need to double check) controlled by 3 different valves at the pump. Two are more like jet returns in the swimout steps in the deep end. Maybe shutting those off more in order to create more circulation in the shallow end (where this algae keeps returning) will help as well. It seems I've never licked it since it started last summer. And I'm quite confident I've correctly completed slam by passing all three tests.....several times.

I've never taken it to mustard shock level however. Going there now. Hose is in the water along with vacuum parts and everything.

 

[JasonLion]

Simply following the SLAM instructions is not sufficient. You need to follow the special mustard algae instructions in the solving problems area of Pool School.

 

[AimeeH]

Thanks JasonLion. That is what we are on our way up to now.....with all noodles thrown away and hoses etc in the pool.